This is a single stamp, issued on December 12, 1928. It shows the aircraft used by the Wright Brothers in the first successful flight of heavier than air, powered aircraft. The 1903 flight lasted exactly 12 seconds and covered a distance of 120 feet. The stamp commemorates the 25th anniversary of this first manned flight. This stamp was issued in conjunction with the International Civil Aeronautics Conference held at Washington, D.C.